The present invention relates to a communication system, which performs communication between a terminal and a central control unit, and a control method thereof, and computer-readable memory.
Generally speaking, a terminal having a character recognition unit transfers the result of character recognition in the terminal to a central control unit, and the central control unit performs post-processing such as error correction, search, and storage of the result of character recognition. At this time, if the terminal judges that the accuracy of a candidate for character recognition is low, the terminal informs the central control unit of being unrecognizable by sending a predetermined identifier (hereinafter, this is called a rejection code) to the central control unit as the candidate for character recognition being unrecognizable.
As for the rejection code, probability (hereinafter, this is called similarity) of each recognition candidate character is calculated, and if it is lower than a predetermined threshold, it is judged that the character is unrecognizable. Therefore, as shown in FIG. 17, generally speaking, if frequency of the rejection code (hereinafter, this is called a rejection ratio) is high, that is, if a threshold of the similarity is high, the similarity of the character that is judged to be recognizable becomes relatively high and its correct solution ratio becomes also high. On the contrary, if the rejection ratio is low, the correct solution ratio of the character is apt to be low even if it is judged that the character is recognizable.
Nevertheless, in a communication system that performs communication between the conventional terminal and central control unit, the rejection ratio is inherent, that is, the threshold of the similarity is fixed. Owing to this, for example, if the rejection ratio varies due to a state change of character recognition in each terminal, the central control unit can treat nothing against that, and hence it is inevitable that efficiency of post-processing decrease.